bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Auto merge of #125507 - compiler-errors:type-length-limit, r=lcnr

Browse source 
Re-implement a type-size based limit

r? lcnr

This PR reintroduces the type length limit added in #37789, which was accidentally made practically useless by the caching changes to `Ty::walk` in #72412, which caused the `walk` function to no longer walk over identical elements.

Hitting this length limit is not fatal unless we are in codegen -- so it shouldn't affect passes like the mir inliner which creates potentially very large types (which we observed, for example, when the new trait solver compiles `itertools` in `--release` mode).

This also increases the type length limit from `1048576 == 2 ** 20` to `2 ** 24`, which covers all of the code that can be reached with craterbot-check. Individual crates can increase the length limit further if desired.

Perf regression is mild and I think we should accept it -- reinstating this limit is important for the new trait solver and to make sure we don't accidentally hit more type-size related regressions in the future.

Fixes #125460
This commit is contained in:
bors 2024-07-03 11:56:36 +00:00
commit c872a1418a
54 changed files with 360 additions and 268 deletions
Download patch file Download diff file Expand all files Collapse all files

2
compiler/rustc_mir_build/src/lints.rs
View file

@ -141,7 +141,7 @@ impl<'tcx> TerminatorClassifier<'tcx> for CallRecursion<'tcx> {
return false;
};
let (callee, call_args) = if let Ok(Some(instance)) =
Instance::resolve(tcx, param_env, callee, normalized_args)
Instance::try_resolve(tcx, param_env, callee, normalized_args)
{
(instance.def_id(), instance.args)
} else {

3
compiler/rustc_mir_build/src/thir/pattern/mod.rs
View file

@ -558,7 +558,8 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
let args = self
.tcx
.normalize_erasing_regions(param_env_reveal_all, self.typeck_results.node_args(id));
let instance = match ty::Instance::resolve(self.tcx, param_env_reveal_all, def_id, args) {
let instance = match ty::Instance::try_resolve(self.tcx, param_env_reveal_all, def_id, args)
{
Ok(Some(i)) => i,
Ok(None) => {
// It should be assoc consts if there's no error but we cannot resolve it.